The purpose of this contract is to provide Hepatitis testing support to the Hepatitis Viruses Section of the Laboratory of Infectious Diseases. The Hepatitis Testing Laboratory will support ongoing studies in animals initiated by DIR/LID/HVS. The contractor will test serum samples for markers of hepatitis virus infection in sera from humans and non-human primates with commercially available assays and with non-commercial tests developed and maintained in the Hepatitis Testing Laboratory. The sera to be tested will be supplied by Intramural investigators.